Artificial knee joint



July 17, 1934.

H. H. WENNEBORG ARTIFICIAL KNEE JOINT Filed Jan.l 3o, 1935 ma I /I Y Patented .uy 147, 1934 n i/Claires@ (Clisi-221i* f c My invention relates to lartificial limbs: and -.=:The-rea1=:merits ofthis'adjustableball-bearmoreparticularly tov improvements. in the fknee ing knee jointi willfbe readily Aob'servedv'lhen the structure of an artificial leg; an object `beingin detailsfthe'reof fare studied-andv compared with my invention Yto providea more practical knee certain Well-known ballebearing" joints commonf- I joint and the means operatively connectedvthere lyy found in u seforrV the r'n'arket.llvr l j Y Withi'or holding'.the..artiiiciallegicomfortably --For'instance-dn this ball-bearing knee joint in' place'and when in operation:topreventnthe the` upper .fsh'ankffbl has-"fits" -lower f terminal 3 jointfrom chewing the clothing4 orymakinga providedz'with--a taperedi or.v cone-shaped hole metallicclickingnose asV the joint functions. Affari-d# annularrecess 15 on fone side and 6 on l0 .A further purpose of my invention isto-prothe' 'othertoprovideaiball race for balls 7 on 65 vide a combination ofcooperating mechanical one side and 8 on the other. Yoke member 9 improvements inthe knee structure ofv anfartihasf'yoke arms l0 and 11L respectively provided Vriginal legwhich will result in a dependable-.joint with threadedholes 12 "and ,1 3fand defining the operatiomna comfortable, grippingA of Ythe wearupperf'terminalof-shank 2. I f

-15 ersleg at the side-of vthey knee when in s taI 1 dr -This-ba1l'-bearing-joint includes features which 70 ing7position and. automatic :releasingv dij-'the makeit quiteconvenientto make necessary adgrip when taking i a vsittingf1l0S'1ti ;v I1;the prO- jus'tm'e'nt "totighten'r Yup' the ttings after 'Y they tec'tion o f clth'ingirombecoming pinched in the become'worn y1somewhat.

joint l and a cushioned, y

esistance .in ytheyjoint 'Byobserving'themanner of assembly of this -20 to eliminatemetallic clicking `thereof.` j ointthe merits thereof I will become evident; 75 I attaintheobjectswof -myiinventioni byfthe 'Fo'rinstance -whe'n assembling thef-joint terimproved f eaturesofan artificial leggdescribed minal member 3'of shank 1 isinserted into yoke in the annexed specification, 4 recited infthe 9; between-'"2yokearms-"lo'and '11'. lAThe balls 7 claims .andillustrated in the accompanying ares'etint'ov ballrac'e :Sect-terminal 3` and bolt 45 relation of theseveral partsthereof. v

1:50 member 1 oper .155 knee joint "structure of ain'lartiiicialleg'; comesislightly woi'risleeve 18l maybe :moved dicatelike partsrinthe'nseveral 'flgur'es. 1 threads 15' ofthe boltheal 1 6 are screwed into Referring to the figures;v`v Vj 1; Y, the'fthreaded-hole"131`offyoke`arm lluntil ball :'Fi'gure lis a perspective of ,one of lthe race 17 ofgbolthead L16V comesint'contact'with structures of my invention whichareadapted `to ballsf-'toholdthemin place. f

'30 operate in pairs.Y f fw; After bolt V16`ji`sscrewed'into operative 'posi- 85 ,Figure 2 is a vertical half snectionof the ball; tionY then balls 8 arefinserted intoY ballrace 6 'of bearing'joint forming oneofthe essential `feafshank te'rmir'ia'lv and the'threaded'cone-shapedV tures of my invention@ y v I sleeve 18 is screwedon-to bolt-shank' 14 Ybyfthe Figure 3 is aside view of.V the ball-bearing .knee internalthreads 1-9y of the 'f sleevei-While at the 35 joint shown in Figure 2. f same tinie-v thethreadedf-headf'z off sleeve 18 90 Figure 4 is a perspectiveof theresilient spring screws'finto threads' l2 Aof 'yoke armf 10; since member operatively secured to the upper shank theinterna'l "and external threads of sleeve 18 member .and controlled by the; action of thezballeffectively' vv'orked together' insizea'nd 'pitch thus bearing joint. f causing sleeve 18 to properly engagethreads-t 1'2 v-40 vFigure 5 is ,a perspective of .theyoke member at the same timejthat it engages threads '21 95 of the ball-bearing knee jointdening-the upper of bolt v16..` l' y A Y terminal of the Ylowershank member. Thusfvvhen'sleeve jv 18 is screwedfdovvn to the Figure 6 is 4adetailed .section offthe knee point'where'fitengages'ballsf8thengconetip 22 structure ofmy invention showing the operative of `s1`eevef-1f8 snngglyiits'nto cone-shaped 4 'of shank termialf'permitting shfnk terminal 3 to 100 Referring in detailto `thezpreferred Yconstrue" Vpivotallyl movethere'on. y 'i tion of my inventionandthe manner of opa Sleev'efl` isfprovided With-an endl recess about erating the samel provide as improvements vin threadedfsh'ank 21`ff bolt 16.3 A' lock-:nut 23 is knee structure ofv artificial. vlegs `antupper shank provided 'with "a vcentral 'shankf24 adaptedto l ativelywpvotd to aflower shank fit down in tof'c'ritralrecess 2'5 of sleeve 18 when member 2 throu'gh" an 'adjustable ball-bearing' the? i'rternallthreads`26 fof'lock nut 23 vengage joint having a decidedly novel andpractical con` threadedl shank' 21 of the vbolt 16. This lock nut struction whichl materially improves' the wearing thus has a tendency to hold sleeve lv'from becomfort, convenienceandpracticability'of the eoniing'floofse "a'n'd yetfwhe'n "thefcon'e vtip 2213e-y s) .n su

'gg moves down about the joint.

to permit tip 27 of the cone portion to be slightly filed olf so that sleeve 18 may thus be made to take up the play that existed in the worn joint.

It will be observed that sleeve 18 may be screwed into place by means of a pin wrench adapted to fit into holes 28 thereof while lock nut 23 may be adjusted by a similar wrench engaging wrench holes 29 and bolt 16 may be turned into place by the same wrench operating in wrench holes 30 in the bolt head. Whenlock nut 23 is secured in place resting against the outer face 31 of yoke arm 10 it then pulls on bolt 15 as well as to provide a protection for sleeve i8. Thus the ball-bearing joint is made` practical, durable and adjustable for the purpose intended and with other details of its construction it accomplished more.

For instance yoke arms .10 and l1 are provided with eccentric raised portions 32, 33, 34, and 35 (35 not shown but corresponding in position with 34 on the yoke arm 1l) for-the purpose of holding clothing` up away from contact with the terminal 3 of shank 1 keep the clothing rfrom gettingcaught in the joint. Y

A cushioning wedge 36 of preferably ber or raw hide is inserted at the base 37 of yoke` 9 so as to provide a means of preventing a metallic click during the operation of the joint as the shank members 1 and 2 are moved intoa position -of upright alignment and is held in place by a screw 44. v A spring member 38 is secured by rivets 39 or other fastening means to shank 1 and provided with a padding 40 of cotton-or wool or other suitable padding of material having limited resilient resistance between spring 38 and shank 1 to provide more uniform resistance for the spring. A slot 41 through which shank 1 extends, enables spring member 38 to reach with its free end around to the outside of shank 1 and extend a terminal clip 42 out over the edge of yoke arm 10. Y.

When in normal use spring 38 exerts `a resilient pressure against the sides of the wearers .7 knee just above the knee joint, in which operative position the spring has a tendency to hold an effective resistance against an undesired slipping of the artificial leg when in use.

But when the person wearing the artificial leg sits down that spr-ingy pressure is not needed. I therefore provide as an integral portion ofv yoke arm l() a cam 43 which when shank l is moved down to asitting position of the wearer has a tendency` to lift clip 42 of spring 38 as clip 42 When clip 42 is thus lifted the result thereof is to relieve the pressure of spring 38 from against the sides of the wearers knee at a time when such pressure is not needed.

It will be noted in connection with my invention that I provide as one of the novel features ofconstruction thereof a side joint at the knee structurey having its locking arrangement so constructed, as will be observed from study of 5 thev drawing, that when the lock nut is turned to lock the adjustable ball bearing joint for operation the lock nut pulls Von the shank of the bolt while it pushes on the lip of the lower shank while the lip in turn pushes on the sleeve and the sleeve in turn exerts a pressure on the bolt shank toward the head thereof thus locking the operating parts of the ball bearing joint which hold the members in place to the lower shank leaving the lower end of the upper shank free to move with the extra freedom Aafforded by the aid of the balls of such an adjustable ball bearing joint. It is thus impossible to force the lips of the lower shank fork or yoke portion of the joint out of true parallel alignment while adjusting or locking the joint.

Within the scope of my invention it will be noted that I provided a preferably leather covering 44 for shank member 1 and on the inside of shank l a lacer portion 45 of this covering is Shaped to receive ra resilient padding which with the covering and lacer portion thereof denes a flexible pocket or resilient padding forming an inward enlargement of the covering adapted to aid in holding the articial leg in place by exerting a light pressure against the sides of the natural knee. v

It will be observed that I provide an organization defining an improved articial knee structure which is practical, substantial, and comfortable and wholly within the range of economical manufacture.

Having thus described the vention what I claim is:

l. The combination in an artificial knee joint comprising upper and lower shank members, adjustable ball-bearing joints therefor, a cushioned stop member for the joints, form fitting and padded spring members on said upper shanks `for engaging the side of the human leg above the knee joint, a cam on the outer side of said joints and an integral extension lip on said spring, registering for control by said cam for releasing the spring, from pressure against the side of the leg, Aand said joint having'ecnature of my ince'ntric raised portions on its Vperiphery for preventing clothing from catching in the joint.

2. In an artificial leg having yupper and lower shank members the conibinationV with an adjustable ball-bearing joint connecting said shank membersofacushioned wedge stopA member within theI yoke ofthe joint to prevent metallic sounds when theknee joint functions, resilient spring members-secured to the upper shank members by one end and resiliently padded between the spring and shank; a slot through which theshankv extends and provided with a terminall clip for a' cam adjustment thereof; vsaid lower shank member provided at the joint yoke* thereof with eccentric members adapted to prevent yclothing from getting 'caught fin said joint'and said yoke members of said lower Vshank provided with an integral side cam for automatically lifting said spring by its terminal -clip -when said shank members are 'angles to relieve said Vspring from its pressure against the sides of the knee when the person wearing the artificial limb assumes a sitting position.

3. In an artificial leg having upper and'lower Tlf;

shank members connected by anV adjustable ballbearing knee joint, andl said'joint having the yoke member "thereof von the lower shank provided'with integralperipherial raised portions to guard clothing from the joint, an integral side cam and a detachable cushioning Wedge member withinthe yoke base portion; a resilient spring member secured tothe upper shank member on the inner side by one end and provided with a slot through which said shank extends, an integral terminal clip on said spring registering with and adapted to be lifted by said integral side cam ofthe joint .when said yoke members are moved to aA position at right .angles to each turned at vrapproximately right l said spring having A "ttt other and a cushioning ller between said spring body and said upper shank.

4. In an artificial leg having upper and lower shank members and padded resilient spring stop members operatively secured to the upper shank members for aiding in holding said artificial limb in place, knee joint members comprising as the adjacent pivotally connected terminals of said shank members a rounded bar terminal for the upper shank provided with a hole through the pvot end dening a cone-shaped perimeter thereof and provided on each side with annular recesses defining a ball race, a yoke defining the upper terminal of the lower shank, threaded holes on each arm of the yoke, a threaded bolt having a threaded head adapted to engage the threads of one arm of the yoke and provided with an annular recess co-operating with said recess of the upper shank terminal dening a ball race, and the shank of the bolt extending through the joint, a cone-shaped and threaded sleeve engaging said bolt shank and registering within said cone-shaped hole of the upper shank member tting in said yoke; said sleeve having a flanged threaded head for screw adjustment in said yoke and engaging said bolt shank and provided with a central end recess, and an annular recess on the side next to said corresponding recess of the upper shank terminal also to define a second ball race, a lock nut threaded for screw engagement of said bolt and provided with a central shank registering within said recess of said sleevev and an outer flange of the lock nut engaging said yoke about the threaded hole in the yoke, integral peripherial raised portions on said yoke members to prevent pinching the wearers pants leg in said joint, a cushioning wedge within said yoke base at the end of said upper shank member as a resilient stop member to prevent metallic clicking of the joint and the outer member of said yoke provided with an integral cam for automatically lifting the free terminal clip of said spring member when the person wearing the leg assumes a sitting position for releasing said spring pressure from the sides of the knee which the spring engages when in a standing position.

5. In an artificial leg having a retaining corset and an artificial shank member, an upper shank provided with a retaining spring member fixed thereto at one end of the spring; said spring intermediate its ends shaped to denne a resilient pocket in conjunction with the lower end of the corset member and lower part of upper shank covering; thus to provide a resilient pressure on the sides of the knee of the natural leg when the wearer is in standing position, an adjustable joint operatively connecting and a lower shank defining a knee action with said upper shank and means connected with said joint for automatically releasing said spring on the upper shank from its resilient pressure against sides of the natural knee when a sitting position is assumed.

6. In an artificial leg having lower shank and a pivotal knee joint, an upper shank secured at said pivot and provided with a Ycovering whose lower terminal is shaped to receive resilient padding between the covering and the shankl to define a flexible pocket at the lower end of the shank covering, to facilitate holding the artificial leg in operative position for normally ekerting a light pressure against the side of the natural knee.

'7. In an artificial leg having upper and lower shank members connected by a ball bearing joint that is adjustable, and a bolt having a threaded head and threaded shank, a sleeve provided with a central conical projection, an internally threaded extension head opposite the conical projection and an annular recess dening about the cone portion a ball race; said lower shank having its joint end forked with threaded holes through the arms thereof, one of said arms adapted to receive the threaded head of the bolt and the other the threaded extension head of the sleeve the upper shank member provided with a conical hole through the bottom end for receiving the cone shaped portion of the sleeve; said internal threads of the sleeve made exactly in true turn with the external threads of the head thereof, a lock nut provided with a central threaded hole for engaging the bolt shank thread, a central projection of the lock nut and an end recess in said sleeve adapted to receive said lock nut projection; said lock nut further provided with an annular recess under the head thereof adapted to provide clearance for said sleeve.

8. InV an artificial leg having a retaining corset and a retaining spring and an uppery shank operatively secured thereto, a lower artificial shank member pivotally connected with the upper shank memberV at the knee positions; said upper shank terminatingvat the lower end in a round shape having a conical hole therethrough and a circular recess defining a ball race on each side adjacent said hole; said lower shank having its upper end forked for receiving the upper shank between the arms of the fork; said arms having a, threaded hole through each with the threads of each cut in exactly true turn to each other, a bolt having a threaded head for one of said fork arms and the shank thereof extending through said conical hole of the upper shank and defining an anchoring pin for the joint a retaining sleeve having a conical center portion with a threaded head for engaging the threads of the fork not engaged by the bolt head and inner threads establishing screw connections with threads on said bolt shank in true turn with the threads of the fork engaged by the head of the sleeve; said sleeve and said bolt head provided with annular recesses cooperating with said ball races of the upper shank in the joint for retaining the ball bearing of the joint and a lock nut provided with central threads operatively .engaging said threads of said bolt shank and provided with an annular flange portion engaging the outer surface of said fork of the lower shank member; said fork of said lower shank at the knee joint provided with an integral cam for automatically releasing said spring on the upper shank fromr pressure against the side of the natural knee when a sitting position is assumed and further provided with eccentric raised portions about its periphery to hold clothing away from contact with said joint causing pinching thereof; said fork provided at its base with a tapered wedge of rawhide or fiber and the like to prevent metallic clicking between the adjacent terminals of said shanks in the joint; and means for holding said wedge within operative position.

HENRY H. WENNEBORG. 

